1. Field of the Invention
The present invention relates to an endoscopic fluid control apparatus which controls the flow of fluid in an endoscope.
2. Description of the Related Art
In general, an endoscope comprises an insertion part which is inserted into a body cavity, and a manipulation part connected to a base end of the insertion part. An endoscope also comprises channels through which fluid flows for feeding or suctioning air or water. Movement of fluid is controlled by a fluid control apparatus provided in the manipulation part (see for example, Jpn. Pat. Appln. KOKAI Publication No. 9-84756, Jpn. Pat. Appln. KOKAI Publication No. 2003-52621, and Jpn. Pat. Appln. KOKAI Publication No. 8-299265).
Recently, there has been a proposal for a method in which a single valve device controls both the air feed and suction for channels in an endoscope (Jpn. Pat. Appln. KOKAI Publication No. 2009-18053). This fluid control apparatus is constituted by a cylinder and a piston body. The cylinder is engaged in an attachment tube provided on a manipulation-part body of the endoscope. A protrusion formed on an outer surface of the cylinder engages in an engagement concave formed in an inner surface of the attachment tube. In this manner, the cylinder is detachably attached to the manipulation-part body so as not to easily detach. Between the attachment tube and the cylinder, there is provided a cam mechanism which floats up the cylinder in a direction of falling off from the attachment tube, thereby assisting in the release of the cylinder, as the cylinder rotates.
Further, a metal suction mouthpiece is provided at an upper end of the cylinder which protrudes from the attachment tube. A suction tube is connected to the metal suction mouthpiece. Further, a metal air-feed mouthpiece is provided at a top end of the piston body which protrudes out of the cylinder. An air-feed tube is connected to the metal air-feed mouthpiece.